The formula for the area of a circle is Area = [tex]\pi[/tex][tex]r^{2}[/tex]
Since the radius of the circle is 9 cm, we can plug 9 cm in for the radius in our formula. Now we have
[tex]\pi[/tex] (9 cm)[tex]^{2}[/tex]. Remember that 9 cm [tex]^{2}[/tex] is the same thing as 9 cm × 9 cm.
[tex]\pi[/tex] (9 cm) (9 cm) = 81[tex]\pi[/tex][tex]cm^{2}[/tex]
